If you have a split form, you skip the next two steps. If you use a split ring like me, this information is for you, and these two steps are mandatory! In order to wrap the ring with foil, you will need a piece of foil measuring 51 by 51 cm. This is based on a ring diameter of 30 cm and a side height of 10 cm. If the foil roll you are using is not wide enough, then tear off two pieces and put one on top of one.